Johnson has become unsettled at Goodison Park as Yakubu has dominated the lone striker roll and a number of clubs are keen to offer him regular first-team football.
Black Cats boss Roy Keane has made finding a new striker his top priority this summer and it is thought he has already failed with a £10million bid for the player.
Everton have responded by saying they want £12million which would represent a £4million profit on a player they signed two seasons ago from Crystal Palace.
Wigan bid for Johnson before he went to Everton and are back in the hunt this time around. Whether they will pay £12million is also a question for debate.
Johnson would also have to decide if he wanted to stay in the north with reports recently claiming he would only consider a move back down south, which would make West Ham favourites.